1、)=ones(1,hx)*50;for i=1:hy; v1(i,1)=0; v1(i,hx)=100;endw=2/(1+sin(pi/(hx-1);maxt=1;t=0;v2=v1;n=0;while(maxt1e-6) n=n+1; maxt=0; for i=2:hy-1; for j=2:hx-1; v2(i,j)=(1-w)*v1(i,j)+w*(v1(i+1,j)+v1(i,j+1)+v2(i-1,j)+v2(i,j-1)/4; t=abs(v2(i,j)-v1(i,j); if (tmaxt) maxt=t; end v1=v2;subplot(1,2,1)mesh(v2)ax
2、is(0,11,0,11,0,100)subplot(1,2,2)contour(v2,20) 结果:coef1=dt/(mu0*dx);coef2=dt/(eps0*dx);coef3=(c*dt-dx)/(c*dt+dx);ezold=ez;for now=1:timestep; hx=hx-coef1*(ez(:,2:ymesh+1)-ez(:,1:ymesh); hy=hy+coef1*(ez(2:xmesh+1,:)-ez(1:xmesh,:); ez(2:xmesh,2:ymesh)=ez(2:ymesh)-. coef2*(hx(2:ymesh)-hx(2:xmesh,1:yme
3、sh-1)-. coef2*(hy(2:ymesh)-hy(1:xmesh-1,2: ez(1,:)=ezold(2,:)+coef3*(ez(2,:)-ezold(1,: ez(xmesh+1,:)=ezold(xmesh,:)+coef3*(ez(xmesh,:)-ezold(xmesh+1,: ez(:,1)=ezold(:,2)+coef3*(ez(:,2)-ezold(:,1);,ymesh+1)=ezold(:,ymesh)+coef3*(ez(:,ymesh)-ezold(:,ymesh+1); ez(xmesh/2+1,ymesh/2+1)=sin(now*dt*2*pi*c/
4、25.0); mesh(ez) pause(0.01) ezold=ez;作业3基于Pocklington方程用MoM分析半波对称振子天线:观察天线线径和分段数目分别取不同值对天线阻抗和辐射特性的影响 (半径分别取 0.001, 0.0001, 0.00001,分段数取11,21,31)%初始化参数c=3e-8;r=1;f=c/r;w=2*pi*f;e0=8.85e-12;u0=4*pi*1e-7;a=0.0001*r;L=0.5*r;k=2*pi/r;N=31;dl=L/(N+1);l=L/2-dl/2;lz=-l:dl:1;lzs=lz(1:N);lzm=lz(1:N)+dl/2;lze=
5、lz(2:N+1);%阻抗矩阵元素求解fi=log(dl/a)/(2*pi*dl)-k/(4*pi)*1j;fi_1=exp(-k*dl*1j)/(4*pi*dl);fi_2=exp(-k*2*dl*1j)/(8*pi*dl);z=ones(N,N);for m=1:N for n=1: if m=n fi1=fi; fi2=fi_1; fi3=fi_2; z(m,n)=(k2*dl2-2)*fi1+fi2+fi3); elseif abs(m-n)=1 fi1=fi_1; fi2=fi; z(m,n)=(k2*dl2-2)*fi+fi2+fi3); else fi1=exp(-k*abs(m
6、-n)*dl*1j)/(4*pi*abs(m-n)*dl); fi2=exp(-k*abs(m+1-n)*dl*1j)/(4*pi*abs(m+1-n)*dl); fi3=exp(-k*abs(n+1-m)*dl*1j)/(4*pi*abs(n+1-m)*dl);%电压矩阵求解V=zeros(N,1);V(N+1)/2)=-1*(1j*w*e0);I=zV;Z_in=1/I(N+1)/2);disp(输入阻抗=,num2str(Z_in)I_amp=abs(I);Max=max(I_amp);Iunit2=0;I_amp/Max(1);0;figure(1)h=0:dl/r:L/r;Ithe=
7、sin(pi*h*r/L);plot(h,Iunit2,b,h,Ithe,r,linewidth,2)legend(pocklinton解析值)grid onxlabel(电长度ylabel(归一化电流%方向图theta=0:0.01:2*pi;abs_f=zeros(1,length(theta);for n=1:1: abs_f=abs_f+I(n)*exp(k*(n*dl-L/2)*cos(theta)*1j);abs_f=abs(sin(theta)*dl.*abs_f);Max_f=abs(sum(I)*dl);Far_patten2=abs_f/Max_f(1);theta_2=0
8、:0.1:Far_theory=abs(cos(k*(L/2)*cos(theta_2)-cos(k*L/2)./sin(theta_2);figure(2)polar(theta,Far_patten2,-bhold onpolar(theta_2,Far_theory,orhold offtitle(半波阵子天线E面方向图figure(3)polar(theta,ones(1,length(theta),半波阵子天线H面方向图%半波阵子增益I_in=I(N+1)/2);A=(w*u0)2/(4*pi*sqrt(u0/e0)*real(Z_in)*(abs(I_in)2);G_theta=A
9、*abs_f.2;Max_gain=max(G_theta);Max_gain_dB=10*log10(Max_gain);半波阵子增益=,sprintf(%.4fdB,Max_gain_dB)作业4基于电场积分方程用MoM分析对称振子天线:计算振子总长度分别为0.25 ,0.5,1.5时,振子的输入阻抗和E面方向图。lamda=1;a=0.0001;me=8.85e-12;mu=4*pi*(1e-7);arg=2*pi*(3e-8)/lamda;L=0.2*lamda;k=2*pi/lamda;N=21;dL=L/(N+1);l=L/2-dL/2;dL:N)+dL/2; if n=m Fmn
10、mm=(1/(2*pi*dL)*log(dL/a)-1j*k/(4*pi); Fmnee=(1/(2*pi*dL)*log(dL/a)-1j*k/(4*pi); Fmnss=(1/(2*pi*dL)*log(dL/a)-1j*k/(4*pi); Fmnse=exp(-1j*k*dL)/(4*pi*dL); Fmnes=exp(-1j*k*dL)/(4*pi*dL); elseif abs(n-m)=1 Fmnmm=exp(-1j*k*dL)/(4*pi*dL); Fmnee=exp(-1j*k*dL)/(4*pi*dL); Fmnss=exp(-1j*k*dL)/(4*pi*dL); if n
11、m Fmnse=exp(-1j*k*2*dL)/(4*pi*2*dL); Fmnes=exp(1/(2*pi*dL)*log(dL/a)-1j*k/(4*pi); Fmnes=exp(-1j*k*2*dL)/(4*pi*2*dL); Fmnse=exp(1/(2*pi*dL)*log(dL/a)-1j*k/(4*pi); num=abs(n-m); Fmnmm=exp(-1j*k*num*dL)/(4*pi*num*dL); Fmnee=exp(-1j*k*num*dL)/(4*pi*num*dL); Fmnss=exp(-1j*k*num*dL)/(4*pi*num*dL); Fmnse=e
12、xp(-1j*k*(num+1)*dL)/(4*pi*(num+1)*dL); Fmnes=exp(-1j*k*(num-1)*dL)/(4*pi*(num-1)*dL); Fmnes=exp(-1j*k*(num+1)*dL)/(4*pi*(num+1)*dL); Fmnse=exp(-1j*k*(num-1)*dL)/(4*pi*(num-1)*dL); z(m,n)=1j*arg*mu*dL*dL*Fmnmm+(1/(1j*arg*me)*(Fmnee-Fmnes-Fmnse-Fmnss);fedp=(N+1)/2;V(fedp)=1;I=linsolve(z,V);Z=V(fedp)/I(fedp);pi/100:ftheta=0;length(theta) F(m)=0; F(m)=F(m)+I(n)*exp(1j*k*(n-fedp)*dL*cos(theta(m);F=abs(F);F1=F/max(F);polar(theta,F1,b.-作业5对课程的建议、自己的收获等。通过学习这门与数学和计算机编程联系紧密的课程,我发现自己数学理论知识还不是很扎实,而且自己对MATLAB的使用也不是很熟练,希望自己在今后能够加强对这方面知识的学习。在学习的过程中也锻炼了自己对所学知识的应用,增加了自己的学习兴趣。
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